Re: oops in ioapic_write_entry

From: Yinghai Lu
Date: Wed Aug 04 2010 - 18:07:11 EST


Please check if this one address your concerns.

Thanks

Yinghai

---
arch/x86/kernel/mpparse.c | 88 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 77 insertions(+), 11 deletions(-)

Index: linux-2.6/arch/x86/kernel/mpparse.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/mpparse.c
+++ linux-2.6/arch/x86/kernel/mpparse.c
@@ -173,17 +173,17 @@ static int __init mp_irq_mpc_intsrc_cmp(
{
if (mp_irq->dstapic != m->dstapic)
return 1;
- if (mp_irq->type != m->type)
+ if (mp_irq->dstirq != m->dstirq)
return 2;
- if (mp_irq->irqtype != m->irqtype)
+ if (mp_irq->srcbus != m->srcbus)
return 3;
- if (mp_irq->irqflag != m->irqflag)
+ if (mp_irq->type != m->type)
return 4;
- if (mp_irq->srcbus != m->srcbus)
+ if (mp_irq->irqtype != m->irqtype)
return 5;
- if (mp_irq->srcbusirq != m->srcbusirq)
+ if (mp_irq->irqflag != m->irqflag)
return 6;
- if (mp_irq->dstirq != m->dstirq)
+ if (mp_irq->srcbusirq != m->srcbusirq)
return 7;

return 0;
@@ -195,9 +195,45 @@ static void __init MP_intsrc_info(struct

print_MP_intsrc_info(m);

+ /*
+ * All BUS, and IOAPIC entries are processed already
+ */
+
+ /* check if dstapic is right */
+ for (i = 0; i < nr_ioapics; i++) {
+ if (mp_ioapics[i].apicid == m->dstapic)
+ break;
+ }
+ if (i == nr_ioapics) {
+ apic_printk(APIC_VERBOSE, "intsrc with wrong apic id is skipped\n");
+ return;
+ }
+
for (i = 0; i < mp_irq_entries; i++) {
- if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
+ int ret = mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m);
+
+ /* duplicated entries ? */
+ if (!ret) {
+ apic_printk(APIC_VERBOSE, "Duplicated intsrc is skipped\n");
return;
+ }
+
+ /* same apic/pin, but different bus */
+ if (ret == 3) {
+ /* overwrite wrong legacy one */
+ if (test_bit(mp_irqs[i].srcbus, mp_bus_not_pci) &&
+ !test_bit(m->srcbus, mp_bus_not_pci)) {
+ apic_printk(APIC_VERBOSE, "Wrong legacy entry with same apic/pin is removed\n");
+ assign_to_mp_irq(m, &mp_irqs[i]);
+ return;
+ }
+ /* dump this legacy one */
+ if (!test_bit(mp_irqs[i].srcbus, mp_bus_not_pci) &&
+ test_bit(m->srcbus, mp_bus_not_pci)) {
+ apic_printk(APIC_VERBOSE, "Wrong legacy entry is skipped\n");
+ return;
+ }
+ }
}

assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
@@ -280,8 +316,8 @@ static int __init smp_read_mpc(struct mp
char str[16];
char oem[10];

- int count = sizeof(*mpc);
- unsigned char *mpt = ((unsigned char *)mpc) + count;
+ int count;
+ unsigned char *mpt;

if (!smp_check_mpc(mpc, oem, str))
return 0;
@@ -305,8 +341,9 @@ static int __init smp_read_mpc(struct mp
/*
* Now process the configuration blocks.
*/
+ count = sizeof(*mpc);
+ mpt = ((unsigned char *)mpc) + count;
x86_init.mpparse.mpc_record(0);
-
while (count < mpc->length) {
switch (*mpt) {
case MP_PROCESSOR:
@@ -324,7 +361,7 @@ static int __init smp_read_mpc(struct mp
skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
break;
case MP_INTSRC:
- MP_intsrc_info((struct mpc_intsrc *)mpt);
+ /* check that next pass */
skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
break;
case MP_LINTSRC:
@@ -337,6 +374,35 @@ static int __init smp_read_mpc(struct mp
count = mpc->length;
break;
}
+ x86_init.mpparse.mpc_record(1);
+ }
+
+ /* second pass for INTSRC */
+ count = sizeof(*mpc);
+ mpt = ((unsigned char *)mpc) + count;
+ x86_init.mpparse.mpc_record(0);
+ while (count < mpc->length) {
+ switch (*mpt) {
+ case MP_PROCESSOR:
+ skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
+ break;
+ case MP_BUS:
+ skip_entry(&mpt, &count, sizeof(struct mpc_bus));
+ break;
+ case MP_IOAPIC:
+ skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
+ break;
+ case MP_INTSRC:
+ MP_intsrc_info((struct mpc_intsrc *)mpt);
+ skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
+ break;
+ case MP_LINTSRC:
+ skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
+ break;
+ default:
+ count = mpc->length;
+ break;
+ }
x86_init.mpparse.mpc_record(1);
}

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